Post by Mystique R333 on Jan 11, 2009 21:53:41 GMT 10
I could not find any original sailplan drawings so I had to work from mainsail P and a rough measure of the three pieces of old broken mast. I then decided to lower both the mast and sail-plan to gain stability. Originally, the rig was a fractional with a tapering mast over 11.2 m from keel step (not deck stepped). I decided to change that to a 10 m from keel step masthead and I had 2.5m² cut off the foot of the main sail to allow the mast to be built lower and closer to the previous top of the fractional fore-triangle (over 1 metre lower). Theory gives this less heeling due to lower centre of side force on the sails but how it affects the balance of the rig I won't know till extensive sailing. If my theory calculations are right, we should be able to regain ballance by mast rake of about 300 mm at the top, moving the centre of effort back about 100 mm - time will tell?
You can see the resultant mast and sail plan in the graphic to the right. Click graphic for an A4 PDF verison. Note: the boom has a higher leech as I took more off the leech than luff to keep the centre of force low but gain some headroom. OK,so I won't have the Quarter Tonner racer it once was, but I also don't intend racing with five crew on the rail either, let alone when out for a cruise with Moira. It should be a tamer, safer and less prone to knock down yacht, which is good and if we can sail it flatter, it may even be faster!
This could give a cheap method of detuning a 3/4 fractional rig by cutting the mast down to close to fore-triangle so perhaps a 9/10th rig, for cruising or safer sailing. Here's hoping we'll find it works. We have a number of other Holland 25 yachts nearby to hopefully compare against (mainly masthead from original). Theory and practice hopefully will be close.
My sailplan can be seen here - www.coolmobility.com.au/Yacht/HOLLAND25-Mystique.pdf
Anyone else got old or new sailplans they are willing to share?
You can see the resultant mast and sail plan in the graphic to the right. Click graphic for an A4 PDF verison. Note: the boom has a higher leech as I took more off the leech than luff to keep the centre of force low but gain some headroom. OK,so I won't have the Quarter Tonner racer it once was, but I also don't intend racing with five crew on the rail either, let alone when out for a cruise with Moira. It should be a tamer, safer and less prone to knock down yacht, which is good and if we can sail it flatter, it may even be faster!
This could give a cheap method of detuning a 3/4 fractional rig by cutting the mast down to close to fore-triangle so perhaps a 9/10th rig, for cruising or safer sailing. Here's hoping we'll find it works. We have a number of other Holland 25 yachts nearby to hopefully compare against (mainly masthead from original). Theory and practice hopefully will be close.
My sailplan can be seen here - www.coolmobility.com.au/Yacht/HOLLAND25-Mystique.pdf
Anyone else got old or new sailplans they are willing to share?
